Die for drawing presses



Patented Nov. 27, 1923.

UNITED STATES PATENT Erica;

-REUBEN STANLEYSMITH, OEMILWAUKEE, wIsOONsIN,` AssIoNoa Toe. O. SMITH CORPORATION, OE MILWAUKEE, WISCONSIN,v a ooaroaaTIoN or NEW Yoax.

DIE Eon Dsr'ivvrlacl vraEssEs.

Appiieatio filed February 2o,l 192e. 1 serial No. 537,914.k

To all whom t may concern Be it known that I, REUBEN STANLEY SMITH, a citizen of theUnited States, and a resident of the city of Milwaukee, Vcounty of Milwaukee, and State of Wisconsin, have invented a certain new and useful Improvement in Dies for Drawing Presses; and I do declare the following to be aolear, exact, and complete description ofthe invention, such as will enable persons skilled in the art to which it relates to make and use the same, reference being had to the accompanying drawing for an exposition of the details of some constructional forms in which I have chosen to embody my said invention.

The invention Arelates to the dies used in a press for drawing sheet metal blanks into shaped articles, such, forrinstance, as the channels which constitute the flanged side bars andcross bars of an automobile or other vehicle frame.

The die members constituting the matrix of the presses heretofore employed for this purpose have been formed in shortsections, the right angled abutting ends of vwhich meet in planes which are perpendicular to the plane ofl the matrix. Ina press used for drawing long blanks into shaped articles, such as the side bars of an automobile frame, die sections in a considerable number have been required, the number thereof-be.

ing determined by the length of the article to be drawn. It has been observed, with the usel of' die sectionsV so formed and arranged,

that transverse lines or marks areproduced upon the flanges of the drawn articles at the points where the die sections abut each other, due to the condition'that 4that portion of the margin of the blank whichy forms the ange moves in a fixed path over or parallel to the joint of the 'abutting die sections, during the drawing operation. This development upon the exterior surface of the flange of the channeled side bar .or other article constitutes a defectin the'structure, in that the existence of the lines or marks so formed in planes transverse to the length of the bar creates conditions which induce crystallization of the metal thereat, with the result that the structure is weakened at such points.

It is the purpose of my present invention to overcome the objection above noted. I vachieve this result byV forming the endsv of the die sections on lines or at angles which departy from'the perpendiculanso that lsuch abutting ends are lmade to'overlap or otherwise meet each other, andthe joints between the die sections are removed from parallelism with the plane of movement of the materialn to be drawn, when the latter isv forced into the matrix by the pressure applied tothe co-o'perating punch. i

As a result of this varied angular or other arrangement of the jointsbetween the abutting ends of the die sections forming the matrix, the material in being drawn wipes over the diagonal or irregular-lines at the joints of the die sections, and an entirely smooth exterior surface `without the lines or marks referred to is producedon the Hanges of the drawn article. i vThus the causes which` heretofore have tended to the fracture ofthe metal following crystallization in the areas affected are removed. y

'.The novel features of'my invention will be defined rinl the claims appended hereto.

InV the drawings which accompany this specification: l

Figure l is an isometric viewvof the matrix of Ia 'drawing press, showing the arrangey ment of my improved system of dies. Fig.l2 is a vertical section on the line 2;2,- Fig. "l, longitudinally of the matrix,l and showing how the die sections overlap each other at their meeting ends. v

Fig.` B is a vertical sectional view trans versely of thematrix, on the line 3 3, Fig. .1. Fig. 4 is an isometric perspective of one of the die members.l

Fig. 5' showsv aconstruction in which the* endsofthe dieA sections overlap in reversed or contrary directions. 'Y f VvFig. 6 shows a modified formation ofthe abutting ends of the die sections, whereby the latter are engaged along irregularlines; Figs. 7 and 8 are views in elevation and plan, respectively, illustrating the formation of the faces `of the dies` A with minute diagonal grooves, for a `purpose to be described; 1

In the drawing, the numeral ll0 indicates the usual shoe of a drawing press in which the die sections or members 11 constituting a matrix are placed. These die vmembers or sections will be assembled with their opposing faces 12' suitably formed and` ar-l ranged to effect the production of the drawn flanges of an article of desired contour.

Instead of forming the die section or memvends will overlap in the manner illustrated in Fig, 2, when assembled in the shoe. Thev inclined `joints so provided will present what is practically an unbroken vertical surface upon the acting faces 12 ofthe die sections, over which joints. the margins of the blank which are to form the flanges will wipe with a relatively diagonal motion. This action will veliminate the formation of the marks which have heretofore been incident to the use of the dies in which the joints between the sections stand in planes parallel to the path of movement of the material being drawn, and so wholly perfect work will be produced.

The degree of inclination from the perpendicular of the beveled faces 13 on the abutting ends of the die sections 11, should .be uniformi in all of the sections constituting a set, in order that a compact arrangement of the die sections may be secured, and no openings left between such abutting ends, when assembled in the shoe. However, such degree of inclination may be varied in different sets of die sections, but it should be Such in all sets that no space will be left for the lateral extrusion of the metal of the blank under the pressure applied to the punch to force the blank into the matrix of the press. rIhe die sections 11 will be substantially rectangular in crossfsection.

In Fig. 5, I have shown a construction in which the ends of the die sections are beveled in reverse directions, this arrangement tendi ing to an equalization and distribution of vthe pressures when the punch enters .the

matrix.

Fig. 6 shows the. abutting ends of the die sections as formed on irregular vertical lines, as at 14:, which may be varied into other forms than that shown, with like results.

In Figs. 7 and 8, I have shown the vertical face ofthe die sections, the ends of which may be formed at any desired angularity, as provided with minute grooves or scores 15, extending diagonally to the longitudinal plane of the dies, the purpose Vof this construction being to exert a smoothing action upon the outer surface of the Vflanges of the bar, as the metal blank is forced into the matrix of the press. It is Ypreferable that the grooves or scores be arranged insuch proximity that the area of the blank .traversed by one groove will approach or overlap that of the contiguous groove, inorder that the whole surface of the flange may be subjected to the smoothing pressure.

Having thus describedy my invention, what I claimv and 'desire to secure byLetters Patent of theUnited States, is

1. Dies constituting the matrix of a sheet metal drawing press, they said dies being formed in sections with ends which overlap, to eliminate die marks on the exterior of the drawnarticle.- Y i 2. Sectional dies for the matrix of a sheet met-al drawing press, the said dies 'having their abutting ends formedin planes which depart from the perpendicular of the longitudinal lplane ofthe dies, to eliminate die marks on the drawn article.

3. Ina sheet metaljdrawing press, a shoe, and dies therein constituting the matrix,

the said vdies being` formed in sections with their abutting endsangularly arranged to eliminate V.die 'markson the exterior of the drawn article. l c

4. As .an article of manufacture, ra die section for a metal drawing press, substantially 'rectangular in cross-section and having its ends beveled or inc-linedk with relation to the longitudinal plane of the die section.

5. In a sheet metal drawing press, diesy i constituting the matrix thereof, the said dies being formed of sections the ends of Vwhich abut in planes'departing from the perpendicular and with grooves on their faces to exert a smoothing action upon the face of the flanges ofthe article being drawn. f

Y 6. lIn a. sheet metal drawing press, dies having their faces formed with diagonal grooves or scores to exert a.V smoothing pressure upon the face of the'artclebeing drawn.

7'. As an article of manufacture, a diev La. STANLEY SMITH.

Witnesses .W- i WOOLAD MAX GRNEWALD. 

